# CVE-2026-42230: n8n: Open Redirect in MCP OAuth Consent Flow

> An attacker can redirect users to malicious sites via the MCP OAuth consent flow if they deny the request, enabling phishing attacks.

- **Severity:** Medium 5.1 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:N/VA:N/SC:L/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 4 May 2026
- **Updated:** 4 May 2026
- **Also known as:** GHSA-f6x8-65q6-j9m9

## What is CVE-2026-42230?

CVE-2026-42230 is a medium-severity vulnerability in N8n N8n, published on 4 May 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

n8n is an open source workflow automation platform. Prior to versions 1.123.32, 2.17.4, and 2.18.1, the /mcp-oauth/register endpoint accepted OAuth client registrations without authentication, allowing arbitrary redirect_uri values to be registered. When a user denies the MCP OAuth consent dialog, the handleDeny handler redirects the user to the registered redirect_uri without validation, enabling an open redirect to an attacker-controlled URL. An attacker can craft a phishing link and send it to a victim; if the victim clicks "Deny" on the consent page, they are silently redirected to an external site. This issue has been patched in versions 1.123.32, 2.17.4, and 2.18.1.

Weakness: CWE-601 (URL Redirection to Untrusted Site)

## Which versions are affected by CVE-2026-42230?

6 open source packages ship an affected version, including n8n. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `n8n` | npm | All versions | 1.123.32 |
| `n8n` | npm | All versions | 1.123.32 |
| `n8n` | npm | From 2.0.0 | 2.17.4 |
| `n8n` | npm | From 2.0.0 | 2.17.4 |
| `n8n` | npm | From 2.18.0 | 2.18.1 |
| `n8n` | npm | From 2.18.0 | 2.18.1 |

Products: N8n N8n.

## How do I fix CVE-2026-42230?

Upgrade n8n to a fixed version for your release line: 1.123.32, 2.17.4 or 2.18.1.

## Is CVE-2026-42230 being exploited?

There is no known exploitation of CVE-2026-42230 in the wild and no public exploit code.

## Other vulnerabilities in N8n N8n

- [CVE-2025-68613](https://insights.sbomify.com/CVE-2025-68613/): n8n Improper Control of Dynamically-Managed Code Resources (critical 10.0, exploited in the wild)
- [CVE-2026-21877](https://insights.sbomify.com/CVE-2026-21877/): n8n is vulnerable to Remote Code Execution via Arbitrary File Write (critical 10.0)
- [CVE-2026-21858](https://insights.sbomify.com/CVE-2026-21858/): n8n Vulnerable to Unauthenticated File Access via Improper Webhook Request Handling (critical 10.0)
- [CVE-2026-1470](https://insights.sbomify.com/CVE-2026-1470/): n8n Unsafe Workflow Expression Evaluation Allows Remote Code Execution (critical 9.9)
- [CVE-2025-68668](https://insights.sbomify.com/CVE-2025-68668/): n8n Vulnerable to Arbitrary Command Execution in Pyodide based Python Code Node (critical 9.9)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-42230 and fix it if it is affected.

What it is: CVE-2026-42230 is a medium-severity vulnerability in N8n N8n, published on 4 May 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-42230 in the wild and no public exploit code.

Affected packages and fixed versions:
- n8n (npm): affected all versions; fixed in 1.123.32
- n8n (npm): affected all versions; fixed in 1.123.32
- n8n (npm): affected from 2.0.0; fixed in 2.17.4
- n8n (npm): affected from 2.0.0; fixed in 2.17.4
- n8n (npm): affected from 2.18.0; fixed in 2.18.1
- n8n (npm): affected from 2.18.0; fixed in 2.18.1

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-42230/ (Markdown: https://insights.sbomify.com/CVE-2026-42230/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-42230
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-42230
- OSV: https://osv.dev/vulnerability/CVE-2026-42230

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-42230/
Summaries are generated and may contain mistakes; the official description above is the record.